The objective of this project is to investigate mobility, risk behaviors, and infectious disease transmission in at risk groups along major transportation corridors in Mexico, linking North and Central America. Mobility is associated with family separation, cultural changes, poverty, and related high risk behaviors which can spread sexually transmitted infections (STIs) and blood-borne infections. Long-distance trucking routes have been identified as important corridors of transmission of HIV and new viral subtypes. The specific aims of this project are: 1) to gather information on trucking company policies and several major trucking routes linking the Americas; 2) to assess the context and type of high risk sexual and drug using behaviors and HIV prevalence among a) high risk long-distance truck drivers whose routes pass through Mexico and b) female sex workers (FSW) with truck driver clientele; 3) to characterize the genetic diversity of HIV in truck drivers and FSWs in two major transportation corridors in Mexico - linking North and Central America. To meet Aim 1, we will consult transportation companies and officials, supplemented with information obtained from truck drivers in Aim 2, to digitally map trucking routes and gain an understanding of current health and work policies of their employees. To meet Aim 2, we will conduct 100 interviews with high risk truck drivers and 100 with FSWs in the largest northern Mexico/U.S. commercial freight corridor (Nuevo Laredo) and along the Mexico/Guatemala border (Ciudad Hidalgo). Interviews will include questions on trucking routes and stops, risk behaviors, HIV/STI knowledge, and access to health services; all will be screened for HIV and syphilis via rapid testing. Additionally, 15 face-to-face, in-depth interviews with truck drivers will be conducted in each city in order to provide information on the context of risk behaviors and data to generate new hypotheses. To meet Aim 3, we will sequence HIV-1 samples from FSWs and trucker drivers found to be positive in Aim 2. HIV sequences will allow us to assess if recombinants or drug resistant strains of HIV-1 have appeared in these cities. As major trucking routes have been identified as important corridors of disease transmission in other settings, they may be one of the first places new HIV subtypes will be identified. This project is timely as HIV prevalence is on the rise along both the U.S./Mexico and Mexico/Guatemala borders, regions where we have already formed a number of binational collaborations. Further, we will be able to explore the effects of a pilot program that began in 9/07 that allows Mexican and U.S. truck drivers to make deliveries in each other's respective countries. The proposed project, which will generate preliminary data for a larger study and strengthen HIV/drug use research capacity in Mexico, is expected to lead to a better understanding of factors associated with risk behaviors in truck drivers and may help to influence policies in order to reduce the transmission of infectious diseases in North America. [unreadable] [unreadable] [unreadable]